Automatic balance-draft appliance.



G. G. G. GRAY.

AUTOMATIC BALANCE DRAFT APPLIANCE. APPLIOATION FILED MAY 6, 1907. RENEWED AUG. 27, 1910. 988,935r

www.mhm m I? 3 SHEETS--SHEET 1.

Patented Apr. 4, 1911.

G. 0. G. GRAY. v AUTOMATIC BALANCE DRAFT APPLIANCE. APPLICATION FILED MAY 6, 1907. REHEWED AUG. 27. 1910.

988,935. PatentedApr. 4, 191 1.

a SHEETS-SHEET z /9 1 i I tb a 7465mm. jnvcnfor j rL-l GeovgeGQGrcg' UNITED. sTATE s PATENT OFFICE.

Gnonor: o. e. GRAY, orrnvn MAWR,*PENNSYLVANIA.

AUTOMATIC BALANCE-DRAFT APPLIANCE.

Specification of Letters latent.

Patented Apia '4, 1911.

Application flied May 6, 1807, Serial No. 371,958. Renewed August 27, 1910.' Serial No. 579,345.

To all whom it may concern: I

Be it known that I, GEORGE C. G. GRAY,

a subject of the King of Great Britain, re-

.matically maintain a balanced draft for steam generators, such as boilers and heating plantsyto automaticallyregulate a forced draft for a steam: plant which shall be uniform inpressure, to thereby et the maximum'efiiciencyfof the fuel use tonprevent undue expansion and contraction of the boiler due to variations of temperature, and

. in general, to prolong the durability of the boiler and reduceto a minimum the employment of manual labor required forthe prodllCtiOIl-.Of an adequate and regular amount of power. I

To the end sought there are coiiperative devices employed to govern the incoming draft and the outgoin of the rod'uc ts of combustion which are My set ibrth in the specification and pointed out in the claims.

The invention is illustrated in the accompanying drawings where similar-reference characters indicate similar parts wherever employed, in whicl1,---:

Figure 1 is a general view of one type of boiler with the coiiperativedevices inrelative position, somegof, the parts being in section. Fig. 2 is acentral vertical section of-the steam. pressure regulating valve. Fig. 3 is a central section of the bleeder valve -for controlling the blower engine. Fi 4 is a section of the fluid (oil) seal and oat operative by the products of combustion within theboilers inclosure, and by the atmospheric pressure exterior to the said inclosure; and also a section of the bleeder valve for controlling the damper. Fig. 5 is a central vertical sectiou'of a diaphra and attachments, as a modification which may be employed instead of the liquid seal shown in Fig. 4,- to control the damper bleeder valve.

The appliances herein described are adaptzed for employment with any form of steam From the reservoir a pipe 23 compressed air to case 24 of the blower generator having forced draft, but for the purposes of illustration there is shownthe simple type of return flue boiler 1, inclfil'ed' by Walls 2, 3, 4, 5 and an arch 6, forming an inclosed combustion chamber of which the fire space 7 and flue 8 are a part, a stack 9 forming the outlet therefrom to the atmosphere. H

Below grate 10 there is an ash pit 11 into whichv a flue 12 leads fromblower 13 operated by engine 14. 'A pipe'15 supplies steam to the engine from boiler 1-, and a throttle valve .16 gauges the flow, the engine having the usual bypass and stop valves for use if the throttle valve requires to be re-= moved.

Located above'the boiler there is an aircompressor 17 of any suitable construction and driven by a motor 18 which may be of any form suited to the most available power. The compressed air is delivered to and stored in a reservoir 19 through a reducing valve 20 which maintains a constant pressure in the reservoir, indicated b gauge 21. elivers the bleeder valve, shown in detail in Fig. 3; wherea passage .25 connects supply pipe 23 and delivery pipe 26, the passage being controlled by limit screw 27 A-port 28 connects passage to a valve chamber 29 which has at its lower part a valve seat 30 with a passage 31 therethrough, in which is a stem'32 of less diameter than the passage,

to permit air to escape when the valve is raised. A valve 33 is attached to the stem,

a flange 34 is also attachedat theopposite end, and a spring 35 in chamber 29 holds the valve normally closed over passage 31.

' Below ,the bleeder valve just described there is a steam pressure regulating valve; shown in detailin Fi 2, wherea diaphragm 36 is in case formed y parts 37,38 with a. pipe 39 connecting the under side of the diaphragm to boiler 1; above case part 37 there Is a spring case 40 covering a long flexibleand sensitive spring 41, mounted on, dia- 1 phragm 36 and with its upper end resting in an adjustable seat 42 screw threaded 'to case 40, adjusted by hand wheel 43 to re'gu late the springs tension, and secured by i look nut 14. A stem 45. is attached to dia jacent to valve 60 there is a liquid seal, also v outer end attached to 'a rod 83 l1avinga turnon the" 'bar. '-Pipe 62 is 1n communication 9 see phragm 36 and passes upward and outward throu 11 seat 42 and has at its upper end a l ush utton 46 screw threaded to stem 45, or adjustment, locked by a nut 47, and

adapted to abut and push u flange 34.

Pipe 26 leads to the un erside of a diaphragm 48 having a-semi-case 49, and a centrai stud 50 carry ng a lever 51 fulcrumed to i case 49 at- 52 and guided at 53, and at its outer end it is attached to a rod 51 having a turnbuckle-55connectin it to rod 56 which is attached t o lever '57 of throttle 16. Pipe 59 forms a connection from reservoir 19 to the damper bleede'i; valve ,GOshownin detail" in Fig. 4, the pipe 59 being in communicai fi with a. passage 61 lcadlng to a pipe 62. A screw 63 intercepts and regulates the flow through assage-6L. lfiom passage 6-1 there is an outet (it to the atmosphere, throu h a nipple 65 screwed to the valve. Locate ad- 7 shown in detail in Fig.4, and preferably using cites a seal,'on account of its non-evaporation, and comprising agas eoinpartment, 66 in communication, with the combustion chamber surrounding the boiler l, bya pipe 67; within the compartment there is a liquid receptacle 68 connected by, a passage 69 to another liquid receptacle 7 0 with an exposed top. W 'thin receptacle 70 there is an open top float T1, andattached thereto'is a bar 72 which" at' its opposite end is-i fulcrumed' to a lug 7am valve 60. At a point above outlet 64' a seat. 74; of'soft material is removably secured by a spring clip. 7 5 secured to bar 72, and eaf-adjustable counter-poise 76 is placed with-a diaphragn i case 77; having a dia hr'agm 7 8 \vitlra -"central stud 7 9 carrying at. ever 80 fulcrunied at one end to a lug S1 of the vdia'phragin cas'e, guided at 82 and its buckle 84L which adjustably secures it to a. rod 85 attached toian'ar'ln 86 which operates damper '87 inrstacktl; a a M In F is shown a modification for i Ji \"il-lVG (30, in lieu-of the "0 re described. lipe67 as is attached to a lower n'g a-diaphragm 89 covc 90'. A rod 91 is attached w l'ph't In -extends u fnvard and is guidetllthrough-cap'32, At its top it has an adjustabldpus'li button !)3, loclwd hy a nut, 94' an d ada pt ed to; opml'al'e 1 ha 1' 72. 'l-he,opal-atriawhine n'iechanis'm set forth as *fbllQWS; aqcnnstan t' pressure'oit' air is maintained in reservoir 19 by compressor 17 and it nmtmf'l-S th i'in'igh reducing valve 20, and-i. 'ipplic'zd through pipes 23', liloml'm' v: 1l'vl':"c:isea2 :iiictp n ditto diaphragm "l8 which ennui-m 'thrinfle valve 16 of motor l l fm-n maingrmom-v.- l-i'at a. uhit'm'm speed while :i liked makinnun steam pressure is in use. lVith an ,accumulationoi': excessive steam pressure the diaphra 'm 36' will'ope'rate push button 46 to raise leeder' valve 33; the air oressure .will then be released, through t e valve, from diaphragm 48 and weight'95 will cause throttle 16 to slow the blower 13.- Meantime the pressure of the gases in the combustion chamber will decrease on account of the pull of thestaek, and this will cause a partial vacuum in compartment 66 and a decreased pressure on the liquid in receptacle 68 causing it to rise, and the liquid in receptacle 70 and its floatto descend andclose bleeder valve 60 so that air pressure will be exerted on ,diaphra 78 to close damper 87. As the draft of stack 9 decreases the pressure on the liquid in reccptacle 68 willincrease until the working;

pressure of the gases is reached Then as the steam pressure decreases the diaphragm 36 will descend and'bleedervalve 33 be closed. Compressed air will again operate diaphragm 48 to openthrottlelfi to start I blower l3. Thus-an excess-of steam pressure orany variation bet-ween the gas-pressurem the combustion chamber, and atmospheric pressure, automatically regulates theblower and the damper to, again restore the equilibrium between the gases inthe combustion chamber "and the atmospheric pres sure exterior to the boilers inelbsure. It has been found by e'khaustim tests and experiments that a very slightvariation ofpr,es sures between the gases due to combustion and the e x'tcrioratmospheritz pressure is sufli; cient to operate these appliances, and that any maximum or 11'1innm1m variation of allowed steam pressure is of very rare occurrencc; I

I claim.

1. The combination with a furnace, of a smoke stack having a damper; an air reservoir and a compressor tot-supplying compressed airto the reservoir; mechanism ac tnatcd by fluid pressure and "embracing a blccder valve for controlling the movement of the dan'lpcrtaml snpplenu'ntal means embracing a liquid seal ":uztilattul by lgas "pres sure from the furnace-to control the bleedervalve. I p

2; The con'xhination'with a boiler and furnace, iitasmoke stack havingfiadamper;

a blower in connection with the tu'i.'nace;,,a 'motor for operating the blowerfmeans for compressed air; an air stratum-toil'(lia. )hragm reservoir;

a hlecder valve intvrn'lokllate thediaphragui f a rd reservoir; steam actuated means ilijcon nection with the boiler to operate the bleeder name to this specification in the presence of valve; mechanism actuated by fluid pressure two subscribing witnesses. for controlling the movement of the damper; and means actuated by the gas pressure GEORGE GRAY 5 in the furnace for controlling the said mech- Witnesses;

anism actuated-by fluid pressure. v R. O. WRIGHT, In testimony vvnereof I have signed my WILLIAM C. STOEVER. 

